According to a study from the University of Waterloo the more diverse your friendship group the more likely you are to engage in strategic voting, which can lead to better electoral outcomes for the entire population.
The study further found that the more closely we associate with friends and colleagues who share a similar ideology, the more likely our view of the world is reinforced. This well-known property of social networks is known as homophily (often called the echo chamber effect) and is perhaps what’s behind the adage that birds of a feather flock together.